To meet the demand for wireless data traffic having increased since deployment of 4G (4th-Generation) communication systems, efforts have been made to develop an improved 5G (5th-Generation) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘beyond 4G network’ or a ‘post LTE system’.
The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation and the like.
In the 5G system, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.
Meanwhile, wireless backhaul schemes may break down into point-to-point (PTP) wireless backhaul and point-to-multipoint (PMP) wireless backhaul. PTP wireless backhaul offers one-to-one communication between one transmitter and one receiver. In PTP wireless backhaul, accordingly, the respective antennas of the transmitter and the receiver are commonly installed in fixed directions that give the optimal performance with respect to each other while generating very narrow beams. Here, use of the higher frequency may further narrow beams generated by antennas with the same size while increasing antenna gain. Therefore, PTP wireless backhaul is more advantageous for high frequency and benefits in light of less interference and excellent communication performance through an increased antenna gain. However, the need of being installed with beam oriented accurately at the position where line-of-sight (LOS) is attained results in wireless backhaul being primarily intended for broad service coverage macro base stations, but not adequate for base stations with relatively smaller coverage (referred to, hereinafter, as small cell base stations).
In PMP wireless backhaul, meanwhile, one hub node (HN) connected with a wired backhaul offers a network connection by wirelessly communicating with multiple remote backhaul nodes (RBN). Conventionally, PMP backhaul adopts antennas with a large beam width of about 60 degrees to about 90 degrees at 6 GHz or less. For the reasons, PMP backhaul, despite being capable of communication even under a non-line-of-sight (NLOS) environment, is vulnerable to interference and exhibits poor communication performance due to the backhaul's decreased antenna gain. Thus, PMP wireless backhaul gives more advantages to small cell base stations that have reduced communication capacity but require easy installation of multiple RBNs regardless of position.
Recently, vigorous research and 3GPP long term evolution (LTE) standardization are underway for heterogeneous cell technology for adding small cells in macro cell service coverage for maximized service areal capacity. As a result, future mobile communication systems are expected to present significantly increased small cell capacity due to coexistence of a number of small cells in macro cells. However, conventional PMP wireless backhaul cannot afford to meet capacity requirements for future small cells due to tiny communication capacity. Conventional PTP wireless backhaul costs a lot for installation and operation, albeit with more communication capacity than that of PMP backhaul. Therefore, a need exists for schemes for increasing small cell backhaul capacity in future mobile communication systems.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.